[PATCH v3 6/8] jscript: Return the correct string for Object.toString(null) in ES5+ modes.

[Gabriel Ivăncescu]

Nevermind, it looks like the checks are needed. Builtins can still end 
up with NULL or undefined in ES3, because the check in apply or call 
only converts to object when they are *not* NULL or undefined. So I 
guess it was correct.